fetch-pack: prepare updated shallow file before fetching the pack
[gitweb.git] / fetch-pack.c
index 6d8926a5504a6cd93e19860f85d58816bdd5c222..6b5467c6dec9645f53d83cdad2467a158db622c0 100644 (file)
@@ -20,6 +20,8 @@ static int no_done;
 static int fetch_fsck_objects = -1;
 static int transfer_fsck_objects = -1;
 static int agent_supported;
+static struct lock_file shallow_lock;
+static const char *alternate_shallow_file;
 
 #define COMPLETE       (1U << 0)
 #define COMMON         (1U << 1)
@@ -36,7 +38,7 @@ static int marked;
 #define MAX_IN_VAIN 256
 
 static struct commit_list *rev_list;
-static int non_common_revs, multi_ack, use_sideband;
+static int non_common_revs, multi_ack, use_sideband, allow_tip_sha1_in_want;
 
 static void rev_list_push(struct commit *commit, int mark)
 {
@@ -172,8 +174,8 @@ static void consume_shallow_list(struct fetch_pack_args *args, int fd)
                 * shallow and unshallow commands every time there
                 * is a block of have lines exchanged.
                 */
-               char line[1000];
-               while (packet_read_line(fd, line, sizeof(line))) {
+               char *line;
+               while ((line = packet_read_line(fd, NULL))) {
                        if (!prefixcmp(line, "shallow "))
                                continue;
                        if (!prefixcmp(line, "unshallow "))
@@ -215,17 +217,17 @@ static int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
 
 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 {
-       static char line[1000];
-       int len = packet_read_line(fd, line, sizeof(line));
+       int len;
+       char *line = packet_read_line(fd, &len);
 
        if (!len)
                die("git fetch-pack: expected ACK/NAK, got EOF");
-       if (line[len-1] == '\n')
-               line[--len] = 0;
        if (!strcmp(line, "NAK"))
                return NAK;
        if (!prefixcmp(line, "ACK ")) {
                if (!get_sha1_hex(line+4, result_sha1)) {
+                       if (len < 45)
+                               return ACK;
                        if (strstr(line+45, "continue"))
                                return ACK_continue;
                        if (strstr(line+45, "common"))
@@ -245,7 +247,7 @@ static void send_request(struct fetch_pack_args *args,
                send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
                packet_flush(fd);
        } else
-               safe_write(fd, buf->buf, buf->len);
+               write_or_die(fd, buf->buf, buf->len);
 }
 
 static void insert_one_alternate_ref(const struct ref *ref, void *unused)
@@ -346,11 +348,11 @@ static int find_common(struct fetch_pack_args *args,
        state_len = req_buf.len;
 
        if (args->depth > 0) {
-               char line[1024];
+               char *line;
                unsigned char sha1[20];
 
                send_request(args, fd[1], &req_buf);
-               while (packet_read_line(fd[0], line, sizeof(line))) {
+               while ((line = packet_read_line(fd[0], NULL))) {
                        if (!prefixcmp(line, "shallow ")) {
                                if (get_sha1_hex(line + 8, sha1))
                                        die("invalid shallow line: %s", line);
@@ -520,47 +522,37 @@ static void mark_recent_complete_commits(struct fetch_pack_args *args,
        }
 }
 
-static int non_matching_ref(struct string_list_item *item, void *unused)
-{
-       if (item->util) {
-               item->util = NULL;
-               return 0;
-       }
-       else
-               return 1;
-}
-
 static void filter_refs(struct fetch_pack_args *args,
-                       struct ref **refs, struct string_list *sought)
+                       struct ref **refs,
+                       struct ref **sought, int nr_sought)
 {
        struct ref *newlist = NULL;
        struct ref **newtail = &newlist;
        struct ref *ref, *next;
-       int sought_pos;
+       int i;
 
-       sought_pos = 0;
+       i = 0;
        for (ref = *refs; ref; ref = next) {
                int keep = 0;
                next = ref->next;
+
                if (!memcmp(ref->name, "refs/", 5) &&
                    check_refname_format(ref->name + 5, 0))
                        ; /* trash */
                else {
-                       while (sought_pos < sought->nr) {
-                               int cmp = strcmp(ref->name, sought->items[sought_pos].string);
+                       while (i < nr_sought) {
+                               int cmp = strcmp(ref->name, sought[i]->name);
                                if (cmp < 0)
                                        break; /* definitely do not have it */
                                else if (cmp == 0) {
                                        keep = 1; /* definitely have it */
-                                       sought->items[sought_pos++].util = "matched";
-                                       break;
+                                       sought[i]->matched = 1;
                                }
-                               else
-                                       sought_pos++; /* might have it; keep looking */
+                               i++;
                        }
                }
 
-               if (! keep && args->fetch_all &&
+               if (!keep && args->fetch_all &&
                    (!args->depth || prefixcmp(ref->name, "refs/tags/")))
                        keep = 1;
 
@@ -573,7 +565,21 @@ static void filter_refs(struct fetch_pack_args *args,
                }
        }
 
-       filter_string_list(sought, 0, non_matching_ref, NULL);
+       /* Append unmatched requests to the list */
+       if (allow_tip_sha1_in_want) {
+               for (i = 0; i < nr_sought; i++) {
+                       ref = sought[i];
+                       if (ref->matched)
+                               continue;
+                       if (get_sha1_hex(ref->name, ref->old_sha1))
+                               continue;
+
+                       ref->matched = 1;
+                       *newtail = ref;
+                       ref->next = NULL;
+                       newtail = &ref->next;
+               }
+       }
        *refs = newlist;
 }
 
@@ -583,7 +589,8 @@ static void mark_alternate_complete(const struct ref *ref, void *unused)
 }
 
 static int everything_local(struct fetch_pack_args *args,
-                           struct ref **refs, struct string_list *sought)
+                           struct ref **refs,
+                           struct ref **sought, int nr_sought)
 {
        struct ref *ref;
        int retval;
@@ -637,7 +644,7 @@ static int everything_local(struct fetch_pack_args *args,
                }
        }
 
-       filter_refs(args, refs, sought);
+       filter_refs(args, refs, sought, nr_sought);
 
        for (retval = 1, ref = *refs; ref ; ref = ref->next) {
                const unsigned char *remote = ref->old_sha1;
@@ -678,7 +685,7 @@ static int get_pack(struct fetch_pack_args *args,
                    int xd[2], char **pack_lockfile)
 {
        struct async demux;
-       const char *argv[20];
+       const char *argv[22];
        char keep_arg[256];
        char hdr_arg[256];
        const char **av;
@@ -719,6 +726,11 @@ static int get_pack(struct fetch_pack_args *args,
                        do_keep = 1;
        }
 
+       if (alternate_shallow_file) {
+               *av++ = "--shallow-file";
+               *av++ = alternate_shallow_file;
+       }
+
        if (do_keep) {
                if (pack_lockfile)
                        cmd.out = -1;
@@ -767,10 +779,38 @@ static int get_pack(struct fetch_pack_args *args,
        return 0;
 }
 
+static int cmp_ref_by_name(const void *a_, const void *b_)
+{
+       const struct ref *a = *((const struct ref **)a_);
+       const struct ref *b = *((const struct ref **)b_);
+       return strcmp(a->name, b->name);
+}
+
+static void setup_alternate_shallow(void)
+{
+       struct strbuf sb = STRBUF_INIT;
+       int fd;
+
+       check_shallow_file_for_update();
+       fd = hold_lock_file_for_update(&shallow_lock, git_path("shallow"),
+                                      LOCK_DIE_ON_ERROR);
+       if (write_shallow_commits(&sb, 0)) {
+               if (write_in_full(fd, sb.buf, sb.len) != sb.len)
+                       die_errno("failed to write to %s", shallow_lock.filename);
+               alternate_shallow_file = shallow_lock.filename;
+       } else
+               /*
+                * is_repository_shallow() sees empty string as "no
+                * shallow file".
+                */
+               alternate_shallow_file = "";
+       strbuf_release(&sb);
+}
+
 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
                                 int fd[2],
                                 const struct ref *orig_ref,
-                                struct string_list *sought,
+                                struct ref **sought, int nr_sought,
                                 char **pack_lockfile)
 {
        struct ref *ref = copy_ref_list(orig_ref);
@@ -779,6 +819,7 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
        int agent_len;
 
        sort_ref_list(&ref, ref_compare_name);
+       qsort(sought, nr_sought, sizeof(*sought), cmp_ref_by_name);
 
        if (is_repository_shallow() && !server_supports("shallow"))
                die("Server does not support shallow clients");
@@ -808,6 +849,11 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
                        fprintf(stderr, "Server supports side-band\n");
                use_sideband = 1;
        }
+       if (server_supports("allow-tip-sha1-in-want")) {
+               if (args->verbose)
+                       fprintf(stderr, "Server supports allow-tip-sha1-in-want\n");
+               allow_tip_sha1_in_want = 1;
+       }
        if (!server_supports("thin-pack"))
                args->use_thin_pack = 0;
        if (!server_supports("no-progress"))
@@ -827,7 +873,7 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
                                agent_len, agent_feature);
        }
 
-       if (everything_local(args, &ref, sought)) {
+       if (everything_local(args, &ref, sought, nr_sought)) {
                packet_flush(fd[1]);
                goto all_done;
        }
@@ -840,6 +886,8 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 
        if (args->stateless_rpc)
                packet_flush(fd[1]);
+       if (args->depth > 0)
+               setup_alternate_shallow();
        if (get_pack(args, fd, pack_lockfile))
                die("git fetch-pack: fetch failed.");
 
@@ -890,62 +938,52 @@ static void fetch_pack_setup(void)
        did_setup = 1;
 }
 
+static int remove_duplicates_in_refs(struct ref **ref, int nr)
+{
+       struct string_list names = STRING_LIST_INIT_NODUP;
+       int src, dst;
+
+       for (src = dst = 0; src < nr; src++) {
+               struct string_list_item *item;
+               item = string_list_insert(&names, ref[src]->name);
+               if (item->util)
+                       continue; /* already have it */
+               item->util = ref[src];
+               if (src != dst)
+                       ref[dst] = ref[src];
+               dst++;
+       }
+       for (src = dst; src < nr; src++)
+               ref[src] = NULL;
+       string_list_clear(&names, 0);
+       return dst;
+}
+
 struct ref *fetch_pack(struct fetch_pack_args *args,
                       int fd[], struct child_process *conn,
                       const struct ref *ref,
                       const char *dest,
-                      struct string_list *sought,
+                      struct ref **sought, int nr_sought,
                       char **pack_lockfile)
 {
-       struct stat st;
        struct ref *ref_cpy;
 
        fetch_pack_setup();
-       if (args->depth > 0) {
-               if (stat(git_path("shallow"), &st))
-                       st.st_mtime = 0;
-       }
-
-       if (sought->nr) {
-               sort_string_list(sought);
-               string_list_remove_duplicates(sought, 0);
-       }
+       if (nr_sought)
+               nr_sought = remove_duplicates_in_refs(sought, nr_sought);
 
        if (!ref) {
                packet_flush(fd[1]);
                die("no matching remote head");
        }
-       ref_cpy = do_fetch_pack(args, fd, ref, sought, pack_lockfile);
+       ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought, pack_lockfile);
 
-       if (args->depth > 0) {
-               static struct lock_file lock;
-               struct cache_time mtime;
-               struct strbuf sb = STRBUF_INIT;
-               char *shallow = git_path("shallow");
-               int fd;
-
-               mtime.sec = st.st_mtime;
-               mtime.nsec = ST_MTIME_NSEC(st);
-               if (stat(shallow, &st)) {
-                       if (mtime.sec)
-                               die("shallow file was removed during fetch");
-               } else if (st.st_mtime != mtime.sec
-#ifdef USE_NSEC
-                               || ST_MTIME_NSEC(st) != mtime.nsec
-#endif
-                         )
-                       die("shallow file was changed during fetch");
-
-               fd = hold_lock_file_for_update(&lock, shallow,
-                                              LOCK_DIE_ON_ERROR);
-               if (!write_shallow_commits(&sb, 0)
-                || write_in_full(fd, sb.buf, sb.len) != sb.len) {
-                       unlink_or_warn(shallow);
-                       rollback_lock_file(&lock);
-               } else {
-                       commit_lock_file(&lock);
-               }
-               strbuf_release(&sb);
+       if (alternate_shallow_file) {
+               if (*alternate_shallow_file == '\0') { /* --unshallow */
+                       unlink_or_warn(git_path("shallow"));
+                       rollback_lock_file(&shallow_lock);
+               } else
+                       commit_lock_file(&shallow_lock);
        }
 
        reprepare_packed_git();